The IEEE 802.16n System Requirements Document (SRD) specifies a requirement for High Reliability (HR) network. As such, one of the requirements is for the mobile stations (HR-MSs) to communicate directly with each other in the event of network failure. The HR-MS to HR-MS direct communications scenario could for example occur in the event of a disaster where the backbone network is destroyed. The rescue teams (e.g. firemen and police officers) would have to communicate directly with each other without a backbone network in order to provide disaster recovery.